This answer has been featured!

Answer:

Activities like those of Senator Joseph McCarthy (Republican) started in the 1950s. It has come to refer to a broader time era and larger movement of the time. Anyone using such tactics.

Explanation:

Senator Joseph McCarthy (Republican) rose to prominence during the Red Scare of the 1940s and 50s caused by the post World War 2 creation of the Communist Bloc in Eastern Europe, the take over of China by the Communists, the acquisition of nuclear technology by the Russians, and the ongoing Cold War.

He suddenly became nationally prominent in 1950 after a speech where he declared he had a list of Communists in the State Department. He never actually produced such a list even though he had a piece paper in his hand at the time. The number of actual communists listed varied from time to time.

There were a number of investigative committees at work in the U.S. government and over the next few years McCarthy would testified on communist activities before them. Notable in this was the House Un-America Activities Committee (HUAC). A group established by the House of Representatives in 1938 to investigate communist activities in America.

McCarthy's accusations often had a air of fact about them but were unsubstantiated by actual documentation. Persons brought before these committees were often not allowed lawyers, nor allowed to cross examine their accusers. Bullying tactics were used to extract information. The accused were encouraged to accuse others. Lists of names (a Blacklist) were compiled and these people were vilified and often driven from their work and community.

Notable in this was the Hollywood Blacklist in which a number of prominent film writers and directors became unemployable in the industry. Some later resumed work under pseudonyms.

The findings of the committees were often later overturned on procedural grounds or facts in the cases were found to be false. In the hysteria this did not matter and the damage was done. There were a number of suicides attributable to this ostracizing.

Companies and groups across the nation began investigating their employees and members for communist activity. They demanded employees sign loyalty oaths. Again, people were hounded from their work and communities on equally thin evidence and questionable procedures.

The televising of the hearings of the HUAC exposed the unfairness of these tactics and there was a public backlash against them.

Less notably McCarthy accused people of homosexual sex crimes in a similar way. He was occasionally anti-Semitic.

McCarthy was censured by the Senate for his actions and faded rapidly from the spotlight. He died in 1957 while still in office.